Add a better filename to the dynamic import chunk. (#2397)

With this we can see the import name in the filename.
This helps a lot in debugging and analyzing the webpack
bundle.

server/build/babel/plugins/handle-import.js

@@ -45,8 +45,10 @@ export default () => ({
   visitor: {
     CallExpression (path) {
       if (path.node.callee.type === TYPE_IMPORT) {
+        const moduleName = path.node.arguments[0].value
+        const name = `${moduleName.replace(/[^\w]/g, '-')}-${UUID.v4()}`
         const newImport = buildImport({
-          name: UUID.v4()
+          name
         })({
           SOURCE: path.node.arguments
         })